What could this be? something serious?

I went to the dr a week ago. The lymph node on the right side of my neck was very swollen. My throat was sore and sore to touch. He put me on keflex. A few days later, it got really hard to swallow and felt like something was lodged. ANd other node was swollen. I accidentally missed my antibiotics for a day. Now, a week later, my left node is getting pretty swollen and it hurts to swallow. Except now instead of being at the base of my throat, it feels right behind my tongue. I was running about 102.5 for a few days. Temp is gone now though. Has anyone had this prob? Is it something I should really worry about?